Long term effects of azithromycin in patients with cystic fibrosis: a double blind, placebo controlled trial

Background: Macrolides display immunomodulatory effects that may be beneficial in chronic inflammatory pulmonary diseases. The aim of the study was to document whether long term use of azithromycin may be associated with respiratory benefits in young patients with cystic fibrosis. Methods: A multicentre, randomised, double blind, placebo controlled trial was conducted from October 2001 to June 2003. The criteria for enrolment were age older than 6 years and forced expiratory volume in 1 second (FEV 1 ) of 40% or more. The active group received either 250 mg or 500 mg (body weight 1 . Results: Eighty two patients of mean (SD) age 11.0 (3.3) years and mean (SD) FEV 1 85 (22)% predicted were randomised: 40 in the azithromycin group and 42 in the placebo group. Nineteen patients were infected with Pseudomonas aeruginosa . The relative change in FEV 1 at month 12 did not differ significantly between the two groups. The number of pulmonary exacerbations (count ratio 0.50 (95% CI 0.32 to 0.79), p Conclusion: Long term use of low dose azithromycin in young patients with cystic fibrosis has a beneficial effect on lung disease expression, even before infection with Pseudomonas aeruginosa .